create_octaves {gambin}

Reclassify a vector of species' abundances into abundance octaves

Description

Creates abundance octaves by a log2 transform that doubles the number of abundance classes within each octave (method 3 of Gray, Bjoergesaeter & Ugland 2006). Octave 0 contains the number of species with 1 individual, octave 1 the number of species with 2 or 3 individuals, octave 2 the number of species with 4 to 7 individuals, and so forth.

Usage

create_octaves(abundances, subsample = 0)

Arguments

abundances

A numerical vector of species abundances in a community.

subsample

If > 0, the community is subsampled by this number of individuals before creating octaves. This is useful for analyses where alpha is estimated from a standardized number of individuals.

Value

A data.frame with two variables: octave with the name of each octave and species with the number of species in that octave.

References

Gray, J.S., Bjoergesaeter, A. & Ugland, K.I. (2006) On plotting species abundance distributions. Journal of Animal Ecology, 75, 752-756.

Examples

data(moths)
create_octaves(moths)